jakealberts wrote:I have never seen Tri-tip in any supermarkets around here (London, Ontario), does it go by a different name?

Jake, you will never see it in a supermarket. The big packers have it all contracted to restaurants and caterers and other large users.
You need to go to a butcher who has access to a small packer or who cuts whole sides of beef. The tri tip has to be cut from the sirloin before it is split into 2 parts.